Description

AES encryption function. This function behaves like the AES_ENCRYPT function in MySQL. By default, it uses the AES_128_ECB algorithm with PKCS7 padding mode. The underlying encryption is done using the OpenSSL library. Reference: https://dev.mysql.com/doc/refman/8.0/en/encryption-functions.html#function_aes-decrypt

Syntax

VARCHAR AES_ENCRYPT(VARCHAR str, VARCHAR key_str[, VARCHAR init_vector][, VARCHAR encryption_mode])

Returns the encrypted result, where:

• str is the text to be encrypted;
• key_str is the key. Note that this key is not a hexadecimal encoding, but a string representation of the encoded key. For example, for 128-bit key encryption, key_str should be 16-length. If the key is not long enough, use zero padding to make it up. If it is longer than that, the final key is found using a cyclic xor method. For example, if the 128-bit key used by the algorithm finally is key, then key[i] = key_str[i] ^ key_str[i+128] ^ key_str[i+256] ^ ...
• init_vector is the initial vector to be used in the algorithm, this is only valid for some algorithms, if not specified then Doris will use the built-in value;
• encryption_mode is the encryption algorithm, optionally available in variable。

danger

Until 3.0.2, function with two arguments will ignore session variable block_encryption_mode and always use AES_128_ECB to do encryption. So it’s not recommended to use it.

Since 3.0.3, it works as expected.

Remarks

For the incoming key, the AES_ENCRYPT function not directly uses, but will further process it. The specific steps are as follows:

1. According to the encryption algorithm used, determine the number of bytes of the key, for example, if you use the AES_128_ECB algorithm, the number of bytes of the key is 128 / 8 = 16 (if you use the AES_256_ECB algorithm, the number of bytes of the key is 128 / 8 = 32). 2;
2. then for the key entered by the user, bits i and 16*k+i are used to perform an isomorphism, followed by a zero if the key entered by the user is less than 16 bits. 3. finally, the newly generated key is used to generate a new key;
3. finally, the newly generated key is used for encryption.

Example

mysql> set block_encryption_mode='';
Query OK, 0 rows affected (0.10 sec)
mysql> select to_base64(aes_encrypt('text','F3229A0B371ED2D9441B830D21A390C3'));
+----------------------------------------------------------+
| to_base64(aes_encrypt('text', '***', '', 'AES_128_ECB')) |
+----------------------------------------------------------+
| wr2JEDVXzL9+2XtRhgIloA==                                 |
+----------------------------------------------------------+
1 row in set (0.12 sec)
mysql> set block_encryption_mode="AES_256_CBC";
Query OK, 0 rows affected (0.11 sec)
mysql> select to_base64(aes_encrypt('text','F3229A0B371ED2D9441B830D21A390C3')); -- since 3.0.3
+----------------------------------------------------------+
| to_base64(aes_encrypt('text', '***', '', 'AES_256_CBC')) |
+----------------------------------------------------------+
| 3dym0E7/+1zbrLIaBVNHSw==                                 |
+----------------------------------------------------------+
1 row in set (0.14 sec)
mysql> select to_base64(aes_encrypt('text','F3229A0B371ED2D9441B830D21A390C3', '0123456789'));
+--------------------------------------------------------------------+
| to_base64(aes_encrypt('text', '***', '0123456789', 'AES_256_CBC')) |
+--------------------------------------------------------------------+
| tsmK1HzbpnEdR2//WhO+MA==                                           |
+--------------------------------------------------------------------+
1 row in set (0.13 sec)

Keywords

AES_ENCRYPT, AES, ENCRYPT